The Reliability of Dietary and Lifestyle Information Obtained From Spouses in an Elderly Chinese Population

In many health studies of the elderly population, the subjects have cognitive or linguistic impairments, so data need to be collected from surrogates. This study compares dietary and lifestyle information reported by elderly Chinese with those provided by their spouses. Community couples 60 years and older were recruited to participate in an interview. One person from each couple was randomly chosen as the index person. Characteristics concerning the index person were then solicited from that person and separately from his or her spouse using validated questionnaires. For the 128 food items considered, the mean kappa was 0.73 for both frequency (SD 0.18) and amount (SD 0.22) of intake, and more than 70% of the couples had kappa statistics exceeding 0.61. Food items exhibiting high agreement between the spouses include rice, apples, tomatoes, and pork chops. The proportion of perfect agreement was higher than 80% for physical activity, smoking, and tea drinking behaviors. In conclusion, the spouse can serve as a proxy to provide reliable information when his or her partner is unavailable.